Fire extinguishing nozzle



March 7, 1944. B. LARTER 2,343,305

FIRE EXTINGUISHING NQZ ZLE Filed Feb. 17, 1941 Ptenhd M". 7,

UNITED I STATES PATENT OFFICE signer to The Fog Nozzle 00., Los

Angeles,

(Jalil'.I a corporation of California Application February 17, 1941,Serial No. 379,178

5 Claims.

This invention relates to a nozzle for extinguishing fire with a liquidsuch as water, and refers particularly to a type of nozzle in which theliquid or water leaving the nozzle is broken up into a spray or fog. Theinvention relates to the type of fire extinguishing nozzles describedand claimed in the application of William W. Jones, filed June 25, 1940,Serial No. 342,296, Patent No. 2,235,258, issued March 18, 1941. inwhich there is described a form of nozzle in which the liquid leavingthe nozzle is broken up into a form of spray or fog by impinging twostreams of liquid against each other under conditions therein described,operative for causing particles of the spray thus produced to be ofsubstantially uniform size.

In the manufacture of nozzles of the foregoing type it is frequentlydesirable, in order to enlarge the area of the fog pattern which will becreated by the nozzle, to employ a plurality of pairs of orifices in thenozzle. In order for such a nozzle to be fully effective, the spraypatterns formed by each pair of orifices should be properly combinedwith the spray patterns formed by each other pair of orifices so thatthe nozzle will be capable of producing a single spray pattern in whichthe density and size of the liquid particles is uniform throughout. Ifthe spray pattern produced by one pair of orifices fails to properlymeet the spray pattern produced by an adjacent pair of orifices, therewill result an area or a channel between the two spray patterns notproperly occupied by the spray and the emciency of the nozzle inextinguishing fires will not properly extend over the combined area ofthe two spray patterns. on the other hand, if the spray patternsproduced by adjacent pairs of orifices improperly intersect or impingeone against the other, a combined spray pattern will result which may beserrated in appearance and is not uniform with respect to density andsize of water or liquid particles.

It is the object of the present invention to provide a nozzle containinga plurality of pairs of orifices operating in conjunction with eachother to produce a combined spray pattern which is uniform throughout indensity of liquid or water particles and in respect to the size of theliquid or water particles occupying the spray.

I have discovered that a nozzle may be produced having a plurality ofpairs of orifices designed to operate in conjunction with each other toproduce a single proper spray, provided that in the design of suchnozzle certain controlling critical factors are observed. The first ofsuch factors is that each individual pair of orifices is so designed,preferably in the manner described in the aforesaid copendingapplication of William W. Jones, as to be capable of producing a sprayof particles of substantially uniform size through the employment of theproper angular relationship and spacing of the orifices, to cause thecenter point of the impinging jets to be at distances from the dischargefaces of the orifices not exceeding twice the diameter of the orifices,and to cause the inside point of impingement of the jets leaving theorifices to be in advance of the discharge faces of the orifices. Thesecond factor is that the body of the nozzle which provides thedischarge orifices provides a proper fiuid chamber leading to theorifices, which fiuid chamber has a maximum cross-sectional area whichis between eight to fifteen times the combined area of the orifices.

The third controlling factor is the design of the pairs of cooperatingorifices in such manner that the spray patterns produced by adjacentpairs properly meet. Each pair of orifices of such nozzles form twostreams of liquid or water which impinge against each other to break upthe liquid into the form of a spray. Such impingement I refer to as theprimary impingement of the orifices. Where a plurality of pairs oforifices are employed, the spray patterns produced by each pair mustproperly impinge against the spray pattern produced by each adjacentpair, and such impingement I refer to as the secondary impingement of.the liquid or water. Where this secondary impingement is made to occurat a, proper point, ranging'from one-half inch to three inches outwardfrom the first impingement (depending upon the design of the nozzle),the particles of the liquid or water at the point of contact of adjacentpatterns are given greater projected velocity, rounding out the combinedspray or fog pattern resulting from the nozzle, so that the nozzle nolonger possesses a plurality of distinct spray patterns but possesses asingle spray pattern effectively covering a combined area.

The necessary factors to be incorporated in a nozzle to create such adesired secondary impingement, together with various objects andadvantages of the present invention, will be most clearly understoodfrom a description of a nozzle embodying the present invention. For thatpurpose I have hereafter described in connection with the accompanyingdrawing such a nozzle.

In the drawing Figure 1 is an elevation in section of one preferred formof nozzle embodying the invention.

Figure 2 is an enlarged fragmentary section illustrative of the designfactors adhered to in the formation of each individual pair of orifices.Figure 3 is a diagrammatic view on the line 3-3 of Fig. 1, indicatingcertain factors in connection with the form of the water spray producedby the nozzle of the present invention.

Referring to the drawing, I have indicated the principles oi. theinvention as incorporated in a nozzle of a particular form, but it is tobe understood that the specific form of the nozzle may undergo widevariations. The specific nozzle illustrated includes a body I made intwo parts, the part 2 having the socket 3 for attachment to a source ofwater supply and a cap 4. The source of water supply may be any usual ordesired form of leader pipe connected to ahose, or a stationary pipewhere the nozzle is intended to be installed in a stationaryinstallation. The part 2 flares outwardly as at 5 to an annularhorizontally positioned ring or flange d. The part 2 is again reduced indiameter above the flange d, as shown at l, and the upper end isthreaded as indicated at 8 to the cap portion d.

In the reduced portion 8 of the body there is formed a plurality ofpairs of orifices 9. Each individual pair of such orifices is designedin accordance with the factors indicated more particularly in connectionwith Fig. 2 of the drawing. In the drawing, A indicates the angle atwhich the streams of water emitted from the orifices intersect eachother. This angle of impingement may undergo wide variations. The moreacute the angle the further outwardly will be projected the'spray formedby the nozzle, but the spray will cover a more narrow pattern. The angleA is determined by the design characteristics of the purpose which thenozzle is supposed to perform. The orifices 9 should be constructed sothat the distance B, which the streams of water emitted from theorifices travel to the center point of impingement, will be not greaterthan twice the diameter D of the orifices 9. It is the principle of theflow of fluids through orifices that where a solid mass of water underpressure is forced against one side of the orifice, the water leavingthe opposite side in the form of a jet contracts to a minimum area wherethe water is flowing at a maximum velocity at a point at a distance fromthe face of the orifice not exceeding twice the diameter of the orifice.To effect the proper breaking up of the water of the two jets byimpinging the jets one against the other, they should undergo suchprimary impingement where the water is flowing at its of the,primaryimpingement of the two streams should be in front of the mostadvanced part of the orifice surface; or, stated another way, the insidepoint of impingement C of the-two streams should be in front of the linemarked DE. If the inside point of impingement C of the two streams isnot in advance of the line DE, two detrimental results are secured. Oneis that water drips from the nozzle,,and the other is that the waterwhich isprojected ,forwardas a sprayhas not the desired uniformcharacteristics.

Now referringto Fig. 3 of the drawing, this figure illustrates in dottedlines the water pattern produced by such a nozzle when operated underlow pressures. It is to be understood that the plane of the waterpattern a, b, c, d is at right angles to Fig. 3 of the drawing. when twostreams 0! water impinge together at low pressures, there is a solidfilm of water such as indicated at a, b, c, (1 formed near the point ofimpingement, the center of which is the point a. At. larger pressures ofwater the leaf-like pattern a. b, c, d is not observed, but on the otherhand the water immediately at the point of impingement appears to havebeen broken into a spray or fog. If the two streams of water (at lowpressure) were aimed directly at each other, the water fllm patternwould be exactly round, with the impingement point exactly in thecenter. As the streams are directed to each other at reduced angles, theresulting water film pattern is pro- Jected outwardly from the originalaxis, forming the elongated film pattern a, b, c, (1 indicated. Such afilm pattern possesses a maximum width b, c, and I have found that theangle 17, a, c, i. e., through the points of maximum width of the leafand the center of impingement, is identical with the angle A indicatedin Fig. 1, which is the angle of impingement of the orifices.

With the foregoing explanation of the action of each individual pair oforifices, the proper spacing of the pairs of orifices 9circumferentially of the body of the nozzle, in order to form oneuniform spray pattern from the nozzle, will now be explained inconnection with the drawing Fig. 3. As indicated in Fig. 3 of thedrawing each pair of the orifices 9 is placed at a distancecircumferentially around the body I of the nozzle so as to have asecondary impingement of the type indicated. As illustrated, theleaflets a, b, c, d, formed by each pair of orifices, contact theadjacent leaflets at their points b, c of maximum area. When theorifices are so designed to create such a secondary impingement, asingle circular spray is emitted at high pressures from the nozzle,having a substantially uniform density of water particles, all of whichparticles are of substantially uniform size. The water pattern emittedfrom the nozzle no longer possesses the serrated appearance or channelscharacteristic center point of impingement at a distance of .75

inch from the axes of the body I and an impingement angle of 50", aproper nozzle is formed byproviding twelve pairs of orificesone-sixteenth of an inch in diameter. At pounds pressure these orificeswill deliver 24.72 gallons of water per minute. The following is a tableshowing the size orifices which intersect at an angle of 50.

Size of orifice M ll $52)! I! 34!! Length of water leaf at Inches InchesInches Inches Indies low pressure 2 3 6 9 l2 Width of same.. a; 1 its 2%3 acter capable of producing the intended, spray,

the water approaching the rear faces of the orifices must be ofrelatively solid character; that is to say, the advancing water shouldnot be broken or turbulent. In order to carry out this purpose with thetype of nozzle indicated, the head I should have a water chamber ill,the dimension F of which is larger than the diameter of the throat ofthe leader connected with the socket 3, or, in other words, the headshould be enlarged over the dimensions of the approaching stream ofwater. I have found that if the maximum area of the water chamber I!)back of the orifices be roughly considered as that of a circle havingthe diameter F of the longest dimension of the water chamber, this areashould be between eight to fifteen times the total area of the orifices9 of the head.

The nozzle herein described will be found to in effect produce a singlespray of liquid rather than a plurality of sprays from the differentorifice pairs. This single spray is substantially uniform in density ofwater, and the size of the water particles in the spray is substantiallyuniform throughout.

While the particular form of the nozzle herein described is well adaptedto carry out the objects of the present invention, it is to beunderstood of course that the principles of the present invention areadapted to be included in a great variety of nozzle designs and that thepresent invention applies to any nozzle having a plurality of pairs oforifices, whether or not such pairs of orifices are intended to form acompletely circular spray as indicated, and the present inventionincludes all such modifications and changes as come within the scope ofthe appended claims.

I claim:

1. A fire extinguishing nozzle for producing a combined spray patterncomposed of particles of substantially uniform size by secondaryimpingement of the sprays produced by the primary impingement effectedby individual pairs of orifices, which nozzle comprises a body havinga'plurality of pairs of orifices, the orifices of each pair being spacedapart and angularly related in such manner as to cause issuing jets tohave a center point of impingement at distances from the discharge facesof the orifices not exceeding twice the diameter of the orifices and tocause the inside point of impingement of the jets leaving the orificesto be in advance of the discharge faces of the orifices. whereby each ofsuch pairs of orifices is capable of producing at the zone ofimpingementa leaf-like liquid pattern, said pairs of orifices beingarranged and spaced in said nozzle to cause the leaf-like patternsproduced by adjacent pairs of orifices to contact at their points ofmaximum width.

2. A fire extinguishing nozzle for single combined substantially uniformspray from the spray patterns produced by a plurality of pairs oforifices, which nozzle comprises a body having such a plurality of pairsof orifices, the orifices of each individual pair of orifices beingspaced apart and angularly related, the angular relationship and spacingofthe orifices of each pair of orifices being adapted to cause theissuing jets to have a center point of impingement at distances fromone-and-a-half to twice the diameter of the orifices from the outerfaces of the orifices and to cause the inside point of impingement ofthe jets from the orifices to be in advance of the faces of theorifices.

producing a such pairs of orifices thereby being capable of producing aleaf-like water pattern, said pairs of orifices being arranged andspaced in the nozzle body to cause the leaf-like patterns of adjacentpairs of orifices to meet at their edges without substantial tendency tooverlap. v

3. A fire extinguishing nozzle for producing a single combined sprayfrom the spray patterns produced by a plurality of pairs of orifices,which nozzle comprises a body having such a plurality of pairs oforifices, the orifices of each individual pair of orifices being spacedapart and angularly related, the angular relationship and spacing of theorifices of each pair of orifices being adapted to cause the issuingjets to have a center point of impingement at distances fromone-and-ahalf to twice the diameter of the orifices from the outer facesof the orifices and to cause the inside point of impingement of the jetsfrom' the orifices to be in advance of the faces of the orifices, suchpairs of orifices thereby being capable of producing a leaf-like waterpattern, said pairs of orifices being arranged and spaced in the nozzlebody to cause the leaf-like patterns of the adjacent pairs of orificesto meet at their edges without substantial tendency to overlap, the bodybeing provided with a fiuid chamber from which said orifices extend,said fiuid chamber having a maximum cross-sectional area of from eightto fifteen times the combined area of the orifices.

4. A nozzle for producing a combined spray of liquid projecting from thenozzle through proper union of the sprays ejected from the nozzle from aplurality of pairs of orifices forming impinging streams, which nozzlecomprises a body having a plurality of pairs of orifices, the orificesof each pair having axes at an angle to each other which if extendedintersect at a point exterior of the nozzle at a distance not over twicethe diameter of the orifices of the nozzle, the orifices of each pair oforifices being spaced apart sufficiently to together with their angularrelationship produce jets having their inside point of impingement inadvance of the orifices, each pair of orifices producing in a plane atright angles to the plane of the axes of the orifices a leaf-like waterpattern, adjacent pairs of orifices being arranged and spaced apart sothat such leaf-like water patterns produced thereby contact at theirpoints of maximum width.

5. A fire extinguishing nozzle for producing a single circular spraypattern composed of particles of uniform size, which nozzle comprises abody having a plurality of pairs of orifices uniformly circumferentiallyspaced apart with respect to the body, each pair of said orifices beingangularly related, the angular relationship and spacing of the orificesof each pair causing issuing jets to have a center point of impingementat distances from one-and-a-half to twice the diameter of the orificesfrom the outer faces of the orifices and causing the inside point ofimpingement of the jets from the orifices to be in advance of the facesof the orifices, each pair of orifices thus being capable of prodpcing aleaf-like liquid pattern in a plane at right angles to the plane of theangle of impingement of the orifices, the spacing of adjacent pairs oforifices being such that, the leaf-like patterns produced therebycontact at their points of maximum width.

ammon a 1;. mm.

